Electric furnace.



PATENTED APR. 10, 1906.

C'. 0. WINGREN. ELECTRIC FURNAGE. APPLLGATION FILED AUG. 21, 1905.

CHARLES C. WINGRN, OF PASADENA, CALIFORNIA.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented April 10, 1906.

Application tiled August 21,1905. Serial N0.,275,l54;.

To 1J/Z whom it marifoon/cern:

Beit known that I, CHARLES O. WINGREN, a citizen of the United States, residing at Pasadena, inthe county of Los Angeles and State of California, have invented new and useful Improvements in Electric Furnaces, of which the following is a specification.

It is the particular object of my invention central vertical section of the furnace on theA line 2 2 of Fig; 1 looking in the direction of the arrow.

ln the drawings an exterior casing 3, preferably of heavy boiler-iron and cylindrical in form, is provided with a removable cover 4, which cover provides means whereby the material forming the center of the furnace and the material to be heated may be placed within the cylinder and the electrodes 5 and 6 may be properly arranged. These electrodes are preferably of carbon and are secured in binding-posts 7 and 8, which project through the casing and provide means for attaching wires which lead to a source of electrical supply. of the binding-posts are partially slit-ted and provided with upwardly-extending ears 9 and 10, through which bolts (not shown) are passed to draw them together to securely hohl the electrodes. The cover is provided with a dome 11, to which is secured a screw cap or cover '12, provided with a viewingglass 13 to enable the operator to inspect the contents of the crucible.' To the dome is secured a pipe 14, which leads to casing 15 of a valve-chamber and enters the same at port 16. This valve-chamber casing is provided with ports 17, 18, 19, and 20. An air-pump 21 is connected by pipe 22 to the valve-chamber at port 17. This pipe is provided with a clack-valve 23, which opens toward the pump as the piston 24 of the air-pump is moved toward the bottom thereof. This piston is provided with a downwardly-opening check-valve 25. The lower portion of the air-pump is connected by pipe 26 with port 19 of the valve-casing. The valve-gate (Not shown.) The sockets 27 is provided with a passage 28, which passage when the valve-gate is in the position shown in Fig. l connects ports 16 and 17 of the valve-casing and with a second passage 29, which connects ports 19 and 20 of the valve-casing. Pipe 26 is provided with an outwardly-opening clack-valve 30. In preparing my furnace for use the interior of the cylinder is filled with a mixture of sand and coke 31 tothe bottom of the electrodes, which electrodes are insulated from the cylinder by insulation 32 of any suitablematerial. Mica is a very suitable material for thatpurpose. The space between the electrodes is filled with coke 33 to the bottom of crucible 34, which cell is of heat-resisting material and incloses the material to be smelted. As the coke is placed between the ends of the electrodes additional filling matter isplaced adjacent to the electrodes and the coke and af ter the Crucible 34 is placed therein additional coke and filling matter is placed in the cylinder until the same reaches the top of the electrodes, after which the remaining portion of the interior is filled with filling material, as shown in Fig. 2. The cover is then put on and secured in place by bolts 35. 36 in pipe 14 enables the removal and replacement of the cover. The smelting-crucible is provided with a viewing-pipe 37, so that the operator may be able to view the ing smelted. V

In smelting quartz I have found that by the use of an ordinary furnace air-bubbles will remain in the mass when cooled, which renders it of no value. The reason why such bubbles remain is because there is not sufficient fluidity in the quartz when heated to expel the air contained therein. With my improved fu nace almost all the air between the lumps of; quartz may be exhausted while it is being smelted.

In some cases it may be found desirable to put a pressure on the quartz while it is being smelted and after the uartz is melted to eX- haust the air from the(furnace, thereby causing any air that may be in the molten mass to escape therefrom, and then to place a pressure upon the mass while it is cooling. To produce this pressure, I rotate valve-gate 27 so that passage 28 will connect ports 16 and 19 and passage 29 will connect ports 17 and 18 and then operate the air-pump so that air will be forced into the smeltlng-crucible. A gage 38 is provided to indicate the pressure A union Y material that is in the crucibl'e while it is be- IOO IOS

IIO

the dome.

in the Crucible, said gage being Connected to After the furnace has become cool the cover may be removed, when the smelting-crucible and its contents can be easily withdrawn from, the furnace and the Crucible furnished with a new Charge of -material to be smelted and replaced. When air is forced into the smelting zone, a pop-valve 39 is provided to prevent too high pressure.

Having described my invention, what I claim as new, and desire to secure by Letters ]Patent,l is

1. The combination of a metallic air-tight casing composed of a body portion and a removable cover secured thereto, said cover being provided with an upwardly-extendin dome; electrodes insulated from and secure( to said body; resistance material in said Casing between said electrodes; a Crucible in said resistance material between said'electrodes; heat-insulating material Within said casing and surrounding said electrodes and Crucible except at and near the dome a viewingpipe extending from the Crucible upwardly through the heat-insulating material and terminating near the dome; and air-exhaust mechanism connected to said dome whereby the air may be exhausted from the Crucible.

2. rlhe combination of a metallic air-tight casing Composed of a bodyportion and a removable cover secured thereto, said cover being provided with an upwardly-extending dome, a' portion of the top of said dome being transparent; electrodes insulated from andsecured to said body; resistance material in said Casin between said electrodes; a crucible in sai resistance material between said electrodes; a heat-insulating material withinl to said body; resistance material in said casing between said electrodes; a Crucible in said resistance material between said electrodes; heat-insulating material within said casing and surrounding said electrodes and Crucible except at and near the dome; a viewing-pipe extending from the Crucible upwardly through the heat-insulating material and terminating near the dome; an air-compression mechanism connected to said dome whereby pneumatic pressure ma be placed upon the material in the crucib e.

4. An electric furnace composed of an outer casing of heavy imperforate material; electrodes secured to said Casing and insulated therefrom and having binding-posts secured thereto, said binding-posts projecting through said casing; resistance material'between said electrodes; a smelting-Crucible in said'resistance material, said Crucible-having an observation-tube Connected thereto; heat-insulating material in said casing surrounding said electrodes, resistance material and smelting-Crucible j a dome secured to said Casing,- a viewing-glass in said dome; avalve-C'asing provided 4with a plurality of ports; a pipe connecting one of said port-s to said dome ,"an air-pum a pipe Connecting said pump with one of t e ports of the valve-Casing; a Clackvalve in said pipe opening toward said pump, said pipe being connected to said pump above the piston therein; a second pipe Connecting the bottom of said pump with another of thev ports of said valve-casing; a clack-valve in said last pipe opening away from said pump; a downwardly-opening check-valve in the piston 0f said pump; anda valve-stopper in said valve-Casing having two channels t erein', one of said Channels being adapted to connect either of the pipes leading to the pump with the pipeleading to the dome and the other of said Channels being adapted to connect the other pipe With the outside air through ports in the valve-Casing.

In witness that I Claim the foregoing I have hereunto subscribed my name this 14th day rif August, 1905.

CHARLES O. WINGREN. Witnesses:

' G. E. HARPHAM,

HENRY T. HAZARD;- 

